Safety shutoff and control device



1943 H. F. ALFERY SAFETY SHUTOFF AND CONTROL DEVICE 2 Sheets-Sheet l Filed Jan. 13, 1941 Patented May 4, 1943 RTE S 1 Claim. (Cl. 137144) This invention relates to a safety shutoff and control device, and more particularly to a thermoelectric safety shutofi and control device for fuel burners, which device has a valve or other means iorcontrolling the supply of fuel to the burner and a'thermoelectric safety shutoff for automatically shutting off the supply of fuel to the burner upon extinguishment of a flame, such, for example, as a pilot flame.

While the particular device selected for illusmagnet for movement to open and closed posi tions with movement of the armature to attracted and retracted positions, it is to be understood that the invention is not limited to this particular embodiment, but may be employed in all similar forms of devicesby way of example, in devices in which the movement of the armature controls a switch connected. in circuit with a solenoid or other electroresponsive valve which is operable to open and close the fuel supply line leading to the burner.

Due to the minute character of the maximum E. M. F. that can be generated by the heat of a pilot light or other flame or source of heat on a thermocouple and the inability of this minute thermoelectric current to actuate the safety shutoff means to open or operating position,

thermoelectric safety shutoff and'cont'rol devices fuel may pass to the burner and collect unburned;

This unburned fuel presents the danger of asphyxiation and possible explosion when a flame r is applied to light the pilot burner.

One of the main objects of the present invention is to provide, in combination with-the thermoelectric safety means and the reset means for resetting the thermoelectric safety means, a valve or other controlling member having an open or operating position and a safety or closed position and means for obstructing or preventing access to the reset means for performing the resetting operation-except when the valve or controlling member is in closed or safety position.

In the more limited aspects of the invention,

the control valve or other controlling member is mounted to be turned to its open 'or operating and closed or safety positions, and a handle is provided for rotating this valve to its different positions, this handle being disposed to obstruct or prevent access to the reset means, and particularly to an externally accessible part of the reset means when the control valve or other control-' ling member is in open or operating position, and to render the reset means accessible when the controlvalve or other controlling memberis in closed or safety position.

It is also an object of my invention to provide a combined safety shutoff and control device of relatively simple and inexpensive construction and of unitary character, and adapted to be installed and operated conveniently and effectively; also a device of this character which is composed of relatively few parts and which is adapted for convenient and expeditious manufacture and assembly.

Another object of the invention is to provide an improved electromagnet assembly and mounting therefor. g 1

In order toacquaint those skilled in the art with the manner of constructing and operating a device in accordance with the present invention, I will now describe, in connection. with the accompanyingdrawings, one preferred embodiment of the invention.

In the drawings:-

Figure 1 is a fragmentary'and more or less diagrammatic viewshowing'an embodiment of the invention in a fuel supplysystem for a main burner and a pilot burner;

Figure 2 is asectional view through the safety shutoff and control device'shown in Figure 1;

Figure 3 is a bottom plan view of the safety shutoff and control'device as the same is viewed in Figures 1 and 2; and

Figure 4 is a detail section taken on the line 4-4 of Figure 2.

Referring to the drawings, the burner l0,

shown fr agmentarily in Figure l, is any suitable burner.

or preferredmain burner such as the burner of a room or space heater, water heater, floor furnace, oven burner, top burner, or any other A fuel ,supply'pipe II leads to the cured, for example, to a of different thermoelectric characteristics.

trol device as will hereinafter be described, although it is to beundcrstood that the pilot supply tube l5 may be otherwise connected to the fuel supply means therefor within the scope of the present invention.

- The safety shutoff and control device, designated in its entirety at 28, comprises a valve body 2| having an inlet 22 and an outlet 23. Contiguous sections of the fuel supply pipe H are connected to the inlet 22 and outlet 23. The inlet 22 opens into an inlet chamber 25, and the outlet 23 opens from an outlet chamber 25 which is separated from the inlet chamber 25 by a wall or partition 21, An intermediate chamber is provided at 28, and the valve housing 2| has a wall or partition 29 for separating the inlet chamber 25 from the intermediate chamber 28. The wall 29 has a valve opening 38 for placing the inlet chamber 25 in communication with the intermediate chamber 28 when the shutotl' valve member 32 is in open position] The electromagnet assembly and magnet andarmature housing structure comprises a cap nut 35, the inner externally threaded end of which is threaded at 31 into the internally threaded outer end of the adjacent portion of the valve body. A sealing. gasket or washer is preferably provided at 38. The outer end orhead ofthe cap nut36 is of suitable polygonal or other form at 38 for engagement by a wrench or the like for applying the cap nut to and removing same from the valve body. The magnet-housing 42 is in the form of an outwardly opening cup-shaped metal shell mounted on the cap nut 88-for example, by secure pressed fit telescopic engagement of its open' outer end in the cap nut at 43. The housing 42 fits'telescopically in the bore application to and removal from the valve body as a unit with the cap nut 35 and the electromagnet and armature and shutoff valve assembly carried thereby.

' The electromagnet comprises a generally U- shaped magnet frame 45 positioned within the magnet housing 42. The magnet frame 45 is seterminal bushing 41 in the manner more fully disclosed in the copending application of Richard K. Engholdt, Serial No. 328,923, filed April 10, 1940. The coil 48 of the electromagnet is wound around the legs of the magnet frame 48. The bushing 41, the shank of which extends through an opening in the outer end wall of the cap nut 36, is shown as externally threaded for threaded engagement with a nut 50 by means of which the bushing is clamped to the outer end of the cap nut 36. A sealing gasket 52 is preferably placed between the headed inner end of the bushing 41 and the outer end wall of the cap nut 36.

A thermocouple indicated at 55 is placed in position so that the hot junction 56 thereof will be heated by the pilot flame l4 as long as the pilot flame is burning. The construction of the thermocouple maybe similar to that more fully disclosed in Oscar J. Leins Patent No. 2,126,564, granted August 9, 1938, or the construction of the thermocouple and the leads thereformay be of any other suitable or preferred form.-

For the purpose of the present description, suiiice it,to state that "the particular thermocouple 55 selected for illustration comprises an outer tubular metallic thermocouple element 51 and an inner'metallic thermocouple elementm518 e inner thermocouple element 58 is Joined at one end to the outer end of the outer thermocouple element 51 to form the thermojunction 58 which is placed in position to be heated by the pilot flame l4. An inner lead conductor 59 is joined to the inner thermocouple element 58 to form an internal thermojunction 58, and an outer tubular lead conductor 6| surrounds the inner lead conductor and is connected to the outer thermocouple element 51, for instance, through a sleeve 52 to form a third thermal Junction 83. The inner lead conductor 58 is insulated from the outerlead conductor 6|, for instance, by a wrapping of insulation 54 on the inner lead conductor.

is preferably provided between the electromagnet of-the safety shutoff and control device and the ends of the leads 5!! and GI opposite the ends which are connected to the thermocouple ele- 44 in the valve body, preferably for ments. This removable lead connection may be of the form disclosed in,the copending application of Richard K. Engholdt above identified. and is illustrated in that form, it being understood that this connection may be of any other suitable or preferred form. Suflice it for pur-'- poses of this description to state that the inner lead 58 has a connector cone 88 which seats in the correspondingly recessed outer end of the terminal tip 61 and is clamped in contact therewith by a connector sleeve 68. The adjacent end of the outer tubular lead conductor 5| is connected in circuit with one side of the coil 48 through the connector sleeve 89 and the bushing 41, and the other side of the coil is connected to the terminal tip 51, the parts being suitably insulated as shown.

The armature I2 is disposed in the armature and electromagnet housing 42 and is adapted to be held in attracted position against the pole ends of the magnet frame 46 as long as the electromagnet is thermoelectrically energized by the heat of the pilot or other flame on the thermocouple. The armature 12 is of disc-like form, and is secured to the outer end of the reciprocai tory valve stem I3. The attachment of the armature to the valve stem at 14 is preferably sufficiently loose, as indicated, to permit self-accommodation of the armature to the pole ends of the magnet frame by a generally universal moveand a metal valve spring seating member 82' member 32 and'valve seating member 82.

ment of the armature upon the outer end ofthe valve stem. The stem 13 is disposed*generally concentrically of the housing 42 and extends in wardly for reciprocating movement through an opening 15 in the inner end of the housing 42.

The safety shutoff valve or controling member 32 is fixed, for example, by a pin I8 upon the inner end of the valve stem 13, preferably for some relative movement thereon so as to have self-accommodating seating engagement with the cooperating valve seat at the adjacent end of the valve opening 38. Packing 8| of felt or other suitableor preferred material is preferably interposed between the inner end of the housing 42 which seats inwardly upon .a shoulder 83 in'the valve body.

The valve spring 84 is in the form of a coiled compression spring interposed between the safety shutoff valve member 32' and the spring seating member 8 2 and centered, if desired, at opposite ends about integral hub-like portions on the valve The spring 84 resiliently moves the armature 12 to retracted position and the shutoff valve member 32 into seating engagement with the valve seat A quick detachable or removable connection I asrarse 3- 60 to shut oil the flow of fuel through the valve n opening 30 when the electromagnetis deenergized. The valve member 32 is preferably provided with a valve gasket or yieldingvalve facing 86 secured in place by a suitable screw 81 or in any other suitable mannerand adapted for engagement withthe vaiveseat 80 when the valve 32 is closed. Y

For the purpose of resetting the armature 12 to gasket or washer provided at 89'. "The axis of thereset stem 88 is in alignment withthe axis of the valve stem I3. A reset button 9| is secured to the outer end of the reset stem, forexample, by a pin 32. The reset stem 60 is-guided at 93 in the cap 89, and the opening'through which the stem extends is sealedby suitable packing 95. A packing washer is provided at 95, and a reset spring 96 is coiled about the-reset stem and interposed betweenthe washer 95 and the reset "button. The reset button 9I'operates slidingly in the opening 91 in the valve body. A reset gasket 98 may be held in place by a reset gasket cap 99, and the reset stem may carry a member I00 having rib means at I02 5 which cooperates with the gasket 95 when the reset stem is in the position shown in Figure 2.

The co-operation of the rib means I02 with the gasket 98"tendsto prevent the" escape of gas or other fuel from the intermediate chamber 28 along the reset stem '60. The reset stem may, if

desired, be provided with a flow interrupter disc for cooperation with a reset valve seat at the adiacent end of the valve opening 30 to shut off the supply of fuel to the main burner during the resetting operation. However, the present in "ventio'n obstructs access to and thereby prevents operation of the reset means except when the control valve, I05, presently to be described, is

closed, and therefore such flow interrupter-disc "is not necessary and has not been shown.-

The control valve is in the form of a truncated conical plug I05 with its conical. surface seated in acorresponding conical bore I06 in the valve body 2|, The plug I05 is disposed laterally of the intermediate chamber 28 with its axis parallel with the axis of the shutoff valve stem I3 and reset stem 88. Threaded upon the valve body 2| is a spring cap I08. Disposed within the cap I08 and abutting a shoulder I09 on the valve plug I05 a stop or abutment disc or washer IIO.

-A coiled spring I I2 is interposed between the stop or abutment disc H0 and the outer end of the cap I08 and acts to maintain the conical surface turn the same therewith-for example, by splaying the adjacent portion of the'plug and providing the handle I with a correspondingly formed opening for locking engagement therewith. A handle screw I2Iis threaded internally into the outer end of the plug I 05 and has its headed outer 75 and cooperating with the handle to secure'the handle removably in place on the plug.

The outer end of the portion of the valve body =2I upon which the cap I08 is mounted is cut away or removed through approximately one-quarter of its circumference to form an opening I4 I Th'e stop disc IIO isfixed to turn with the plug I05 by splaying the sides of the plug as indicated at I in Figure land forming the opening in the disc IIO of conforming configuration.

The disc III! has a lug I25 which operates in the slot or circumferential Opening MI and limits the rotation of the control valve plug I 05,

in one extremity, with the port H6 in full registration with the opening H8, and, at the other extremity, with the port II6 completely out of register with the opening III! to shut off the supply of fuel to the burner. Intermediate positions of the valve plug I05 between the position in which the port H6 is in full registration with the opening H8 and the position in which the port I I5 is completely out of registration with the opening |I8 provides for supplying different amounts of fuel to the burner to control the same.

As shownin Figure.3, the handle I 20 is of quadrant shaped form or has a quadrant shaped part I28. With the handle in the dotted line po sition shown in Figure 3, the valve plug I05 is completely closed and the quadrant shaped part I28 is completely removed fromlposition obstructingaccess to the reset button 9| so that this button may be manipulated to reset the device. As the handle .120 is turned away from its dotted line position (in a clockwise direction as the device is viewed in Figure 3) to position the valve I05 infull open or intermediate open position, the quadrant shaped part I28 moves to position wholly or partially endwise of the reset button 8|, thereby obstructing or preventing access to the button 9I so that the armature cannot be set to attracted position and the shutoff valve to open position except when the handle is removed from obstructing position by closing the valve I05.

The device may be provided with a plug member I30 threaded into an opening in thevalve body 2| in alignment with the opening H0 and preferably with a sealing gasket or washer IOI interposed between the head of the plug and the valve body.

In the illustrated embodiment of the invention, the tube I5 for supplying fuel to the pilot burner I3 is connected through a suitable connector fitting and a port I36 with the interior of the valve body. The port I36 preferably opens into the valve opening 30 below the valve seat as the device is viewed in Figure 2, and where flow interrupter means is provided for cooperation with a valve seat at the opposite end of the valve opening 30 the port I36 i preferably disposed above the lower end of the valve opening, as shown. The connection through which fuel is supplied to the pilot burner may be provided with means, such as a metering screw (not shown), for adjusting or shutting off the supply of fuel to the pilot burner.

The operation of the device is as follows:

When the pilot light is burning, the heat thereof upon the therrnojunction 56 produces athermoelectric current in the coil '48. The magnet frame 46 and armature I2 are preferably formed of an alloy of relatively low magnetic reluctance and, as a result, the minute or relatively weak thermoelectric current produces a magnetic field of sufllcient strength so that when the armature I2 is placed in attracted position by pushing the reset button 9| inwardly, the magnetic attraction holds the armature in attracted position against the magnet frame with a force greater than the force exerted by the spring 84, thereby holding the shutoff valve 32 in open position as long as the pilot flame is burning.

If the pilot flame is extinguished, the holding action of the electromagnet ceases to be sufficient to hold the armature 12 in attracted position and the shutoff valve 32 in open position, and the tion, and renders the reset button 9| accessible so that it may be pressed inwardly to move the armature to attracted position and the shutoff valve to open position. The closed position of the valve plug I shuts off the supply of fuel to the main burner during this operation, but as soon as the shutoff. valve 32 is opened in the resetting operation, a supply of fuel is set up through the port I36 to the pilot burner.

If the pilot burner is lighted and sets up a thermo-electric current to hold the armature in attracted position and the shutoff valve in open position, the shutoff valve 32 will remain open, and when the reset button BI is released, the spring 96 returns the reset button and stem 88 to their outwardly projected position as shown in Figure 2. The plug or cook I05 may then be rotated to open the port HR to the outlet chamber 26 in order to supply fuel to the main burner. lithe pilot burner is not lighted to produce the thermo-electric current for holding the shutoff valve 32 open, this valve will move to closed position upon release of the reset button iii.

In order to turn on or shut off the supply of fuel to the main burner with the-pilot light burning and the armature "I2 held in attracted position and the shutoff valve 32 held in open position, the handle I2!) is grasped and turned to rotate the valve plug I05. With the port H6 in complete register with the opening II8 as shown in Figure 2, the device is completely open for maximum supply of fuel to the main burner. By rotating the plug until the port I I6 is completely out of register with the opening H8, the supply of fuel through the outlet 23, and thereby the supply. of fuel to the main burner, is completely shut off. Intermediate supplies of fuel through the outlet 23, and thereby to the main burner, are provided by intermediate amounts of registration of the port H6 with the opening H8.

The embodiment of the invention shown in the drawings is for illustrative purposes, and it is to be expressly understood that said drawings and the accompanying specification are not to be construed as a definition of the limits or scope of the invention, referencebeing had to the appended claim for that purpose.

I claim:

In combination, a fiuid'supply conduit, a valve member for controlling the supply of fluid through said conduit, a movable armature'operable to control said valve member, an electromagnet for said armature, a thermocouple connected to said electromagnet for energizing said electromagnet, rectilinearly movable reset means for. resetting said armature to attracted position, a rotatable valve member spaced laterally from said rectilinearly movable reset means and operable to control the supply of fluid through said conduit, and guard means carried by said rotatable valve member for obstructing endwise access to said reset means when said rotatable valve member is open and requiring closing of said rotatable valve member to clear said guard means of said reset means for access to said reset means for resetting operation thereof, said guard means having swinging movement in a plane Wholly beyond the end of said reset means so that said guard means may be swung in either dlrectionfrom obstructing position and with said reset means in its outwardly projected position.

HENRY F. ALFERY. 

